☑ Disc Capacitor As Loop Antenna

The antenna tunes from 10 through 20 meters and is rated for 100 w input. All these loops involve a resonant tuned circuit made up by a multi turn loop coil and a variable capacitor.

How To Read A Capacitor 13 Steps With Pictures Wikihow

0047 Uf 50 Vdc Disc Capacitor All Electronics Corp

Performance Of The Proposed Cpw Fed Slot Loop Antenna With

21 mhzapproximately s unit better on loop.

Disc capacitor as loop antenna. The secondary loop has a variable capacitor to electrically adjust its resonance. If you are using one of my designs shown on these pages you are all set to go ahead. As a bonus the need for an extremely low speed tuning motor is offset by using a simplified drive mechanism.

Also the resonance frequency will vary with temperature changes sunshineweather. N5eses shielded loop receiving antenna. A word about loop antenna design.

On 7 10 and 14 mhz bands. The slot allows for a 120pf 5kv working disc capacitor to be fixed in place to allow operation on 40m. Calculator results for a loop with a diameter of 1 m 32 ft.

A well constructed small loop antenna has a bandwidth that requires re tuning when changing frequency across a band. Loop antenna calculators suggest that a loop of that size can be tune from 40 to 10 mtrs with a variable capacitor of 10 180 pf. Antenna was mounted in vertical orientation.

My loop antenna november 20 2013 14 receive properties of electrically small loops loop antenna is tuned to a resonance on receive by adjusting the tuning capacitor atmospheric noise dominates over receiver noise at hf tuning is narrowband tending to limit received noise gain of a loop may be lower than that of other antennas but. I searched on ebay there is a 40 kv 5 100 pf vacuum variable capacitor for 90. See the tables and plot below.

Pacitor in a day or two using simple hand tools. Do you think would it possibile. A loop with a fixed value capacitor is resonant at a single fixed frequency.

Tuning capacitor warm to the touch at 30 watts when keyed for 30 seconds. Arcing on any band at 30 watts. Alternatively some people use a toroidal transformer and still others use a gamma match.

Changing this to a similar 57pf capacitor allows operation on 30m and without a fixed capacitor the loop will tune on 20m and 17m. The pigtails of the loop connect in parallel with the capacitors. Therefore id like to upgrade my loop antenna with another capacitor vacuum or butterfly.

Can you please help with your advices. No evidence of. The variable capacitor is the biggest decision on the limitations of your antenna.

N5fc is my former call. Mechanically the capacitor consists of. To the pcb and added other ceramic disk capacitors as necessary to resonate the antenna at the frequency of interest in this case 40 meters with the variable at mid range.

By monty northrup n5ese. Some folks use a variable capacitor that is smaller and handles low wattage before arc over. But if you are designing your own loop antenna please read on.

Ldf5 50 based magnetic loop antenna. The kd7s loop tuning capacitor used with a 3 foot diameter loop antenna. Best would be to have a resonant antenna from 30 meters to 10 metersor 20 meters to 6 meters.

Antenna slightly warm on 7 mhz band.